const size=1024*1024;

function upload(start) {
    let fileObj=$("#file")[0].files[0];
    if(start>=fileObj.size){
        $('#fileSize').text('上传完成').css('color','green');
        $('#file').val(null);
        $("#progress-border").css("display","none");
        return;
    }

    //获取文件块的终止字节
    let end=(start+size>fileObj.size)?fileObj.size:(start+size);
    //将文件切块上传
    let fd=new FormData();
    fd.append("start",start);
    fd.append('f',fileObj.slice(start,end));
    fd.append('filename',fileObj.name);
    //post表单提交
    $.ajax({
        url:'/upload2',
        type:'post',
        data:fd,
        processData:false,
        contentType:false,
        success:function () {
            $('#fileSize').text(start+'/'+fileObj.size);
            $("#progress").css("width",start*200/fileObj.size+"px");
            upload(end);
        }
    });
}


function init() {
    let fileObj=$("#file")[0].files[0];
    $("#progress-border").css("display","block");

    //获取文件已经上传的大小
    $.get(
        '/getSize',
        {fileName:fileObj.name},
        function (data) {
            let start=parseInt(data);
            alert(start);
            $('#fileSize').text(start+'/'+fileObj.size).css('color','blue');

            //开始上传
            upload(start);
            if(start==fileObj.size){
                alert("秒传");
                $("#progress-border").css("display","none");
            }
        }
    );

}